NL7905787A - METHOD FOR PREPARING THERMO-CURING FIBER-REINFORCED PLASTICS - Google Patents

Description

St 49231 / Bs / WVR _1 _ -f A / S JOTUNGRUPPEN, Sandefjord, Norway and ELKEM-SPIGERVERKET A / S, Birkeland, Norway.

Process for preparing thermosetting fiber-reinforced plastics.

The invention relates to a process for the preparation of thermosetting fiber-reinforced plastic using unsaturated plastic resin and / or monomers, a catalyst, an accelerator system, and reinforcing fibers.

Unsaturated synthetic resins and monomers such as styrene and acrylates are usually cured by adding (a) an accelerator, and (b) a catalyst.

The plastic material formed by this curing process can be commonly referred to as a thermoset resin. In order to obtain better mechanical strength in a thermoset resin, it is reinforced with glass fiber, carbon fibers and the like.

The curing of the unsaturated resin is usually accomplished by one of two mechanisms: (1) Redox system

The catalyst forms radicals upon exposure to a reducing agent. The most common reducing agent is formed by Co ++ ions.

The mechanism is probably the following (Tobolskv and Mesrobian, Organic Peroxides, Wiley Interscience, New York, 1954): 25 ROOH + Co2t-jRO. + OH ”+ Co3 + ROOH + Co3t -> R02. + H + + Co2 + RO. + Co2 + -> R0 "+ Co3 + (2) Horner-Schlenk mechanism 7905787 ψ _ 2 _

Ar i A number of amines initiate the formation of free radicals when they come into contact with peroxides.

Horner-Schlenk have explained this in the following way (Horner and Schlenk, Angew. Chemie 61, 411,1949): 4 CH-HCH- nw wrtï Jl δ ri 0 § + c6h5? -Oo? C6h5 -> -occ6h5 + c6h5öo .

ch3-N-ch3 + CH, NCH, CHINCH, Λ, μ-, Ai-A, 1 ^ J -occ6h5 -> H \) 'N: -> H CH3

Unsaturated synthetic resins are in most cases used in conjunction with monomers such as styrene and / or acrylates to obtain desired properties both in the treatment phase and in the final product.

An accelerator is usually added to the synthetic resin / monomer mixture, the stability of such a system being relatively long, usually several months. Stability can also be controlled by the addition of an inhibitor, eg hydroquinone.

Immediately prior to use, a catalyst such as methyl ethyl ketone peroxide, cyclohexax nonperoxide, acetylacetone peroxide, benzoyl peroxide or the like is added. __________________ 7905787 *.

-3 -

Once the peroxide has been added, curing begins. The synthetic resin mixture usually gels after 20 to 60 minutes. The product is usually removed from the mold after 4-6 hours; final curing takes place in at least 24 hours.

In the preparation of reinforced thermosetting plastic materials, glass fibers, carbon fibers, polyamide fibers and the like are used as reinforcing materials.

These fibers are distributed and carefully worked into the liquid unsaturated synthetic resin, to which a curing system has previously been added.

This process has relatively little time available, as, as mentioned above, the curing reaction begins as soon as the catalyst and accelerator come together in the unsaturated resin.

Conventional practice has hitherto been to add the accelerator and catalyst to the unsaturated resin (optionally the blends) before the latter is contacted with the fibers.

The invention now relates to a process for preparing a thermosetting fiber-reinforced plastic using unsaturated synthetic resin and / or monomers, a catalyst, an accelerator system and reinforcing fibers, characterized in that a mixture of unsaturated synthetic resin and a catalyst is reinforced with fibers in which an accelerator is incorporated.

According to the invention, the unsaturated synthetic resin 30 may be a polyester, a polyacrylate, vinyl resin, polyurethane, or another polymerizable compound, such as, for example, styrene monomers, or mixtures thereof.

According to the invention, the catalyst used is a peroxide or another type of catalyst, or mixtures of both.

The accelerator system according to the invention is 7905787

Zfc - 4 -: based on compounds of Co, Fe, Mn, V, Pb, amine or another type of accelerator, alone or in combination.

The reinforcing fibers used according to the invention may be glass fibers, carbon fibers, metal wires, polyamide fibers, or other suitable fibrous material, either in the form of untreated fibers, or prepared as a mat, a webbing, a webbing webbing, chopped fiber, or any other prepared status.

10 | The invention also relates to a modification of the above process, characterized in that an unsaturated synthetic resin to which an accelerator system has been added is reinforced with fibers to which a catalyst has been added.

The invention also relates to an agent to be used in the curing of unsaturated synthetic resin by the above-mentioned process, characterized in that this agent contains reinforcing fibers in which an accelerator. system is incorporated.

Finally, the invention relates to an agent for use in the curing of unsaturated synthetic resin by the modified process, as specified above, this agent being characterized in that it contains reinforcing fibers in which a catalyst is incorporated.

According to the invention, only the catalyst, or optionally only the accelerator, is previously added to the unsaturated synthetic resin (mixture), while the accelerator, or optionally the catalyst, is incorporated into the reinforcing fibers.

The curing process then only starts when the synthetic resin and the reinforcing material come into contact with each other. In this way the synthetic resin (mixture) is prevented from gelling in the vessel and in the application equipment. This results in large savings in the form of less loss of raw material, reduced use of tools 7TÓT7T7 -J -______, and easier cleaning with less use of organic solvents, and therefore significantly improved working conditions. The fire hazard is significantly reduced due to the following 5 factors: The handling of peroxide (catalyst) is significantly reduced, since only 1 day requirement of unsaturated resin and catalyst can be mixed in one operation. In addition, the problem is avoided that residues of resin mixture, in which both accelerator and catalyst are added, initiate an uncontrolled highly exothermic curing reaction, which has often been the cause of fires.

Since the hardening process does not start until the reinforcing material with incorporated accelerator 15 comes into contact with the unsaturated synthetic resin with added catalyst, the operator has more time at his disposal, and therefore a greater possibility to arrive at a technically better product.

Example 20 A matte glass fiber incorporating cobalt in an amount of about 300 ppm was used as the reinforcing material in a laminate in which polyester dissolved in styrene, in which 2% methyl ethyl ketone peroxide was added, was used as the unsaturated synthetic resin.

This laminate was cured in the usual manner.

The gelation time was about 40 minutes. Full cure was measured after 9 hours. The remaining monomers on the laminate were found to be about 1.5% after analysis after curing at room temperature for 24 hours.

In this example, cobalt was used as an accelerator, methyl ethyl ketone peroxide as a catalyst, and polyester as an unsaturated synthetic resin (the polyester used was a standard type unsaturated polyester based on phthalic acid and moleic acid dissolved in styrene monomers).

35 It will be understood, however, that those substances can be replaced by other substances specified 7905787 Ö> ‘ί - 6 -; in the conclusions. Also, modifications of such a method can be made without departing from the scope of the invention.

The invention also relates to reinforcing materials in the form of fibers and / or fillers to be used in the above-mentioned preparation of reinforced thermosetting plastic materials.

The invention therefore also relates to on reinforcing materials in the form of fibers and / or j 10! fillers to be used in the preparation of armed! thermosetting plastic / wherein these materials have the feature / that an accelerator system or a catalyst is incorporated in the fibers and / or fillers.

The reinforcing materials, as mentioned before, are characterized in that they consist of glass fibers, carbon fibers, metal fibers, polyamide fibers, or. another suitable fibrous material, either in the form of untreated fibers, or prepared as a mat, i; roving, woven rovings, chopped fiber, etc.

The accelerator system may consist of compounds of Co, Fe, Mn, V or Pb, amine, or another type of accelerator, alone or in combination.

According to the invention, the catalyst may be peroxide or another type of catalyst or mixtures thereof.

The invention further relates to a process for preparing the above-mentioned reinforcing materials, characterized in that the acceleration system or the catalyst is dissolved, emulsified. dispersed or chemically bonded with a known per se prior to this axret being applied to the fibers.

Furthermore, according to the invention, the accelerator-1 system or the catalyst can be dissolved, dispersed, emulsified or chemically bonded with a fiber mat. binder, before applying this binder to: "the mat.

7TÖ ~ 5 7 8 ~ 7 —7 -

Furthermore, according to the invention, the accelerator system or the catalyst can be applied directly to a fiber product in the form of a solution, emulsion, dispersion, or in solid form.

In other words, according to the invention, the more quickly, or optionally the catalyst, can be incorporated into the reinforcing fiber.

As already noted, the curing process does not begin until the synthetic resin and the reinforcing material come into contact, resulting in the previously discussed advantages.

Further examples will now further illustrate the invention.

Example I

15 Application of accelerator systems to the primary fiber.

A. A cobalt compound or other type of accelerator is dissolved in the sizing which is applied to the fiber immediately after it is drawn, thereby incorporating the desired amount of cobalt compound or other accelerator into the glass fiber.

Fiber apret

Vinyl tris-betamethoxyethoxysilane 0.50

Polyvinyl acetate emulsion (50%) 7.60 25 Lubricant (arguad S50) 0.07

Cobalt Acetate (Co (C2H302) .4H2 O) 2.20

Deionized water 89.63 100.00 30 B. A cobalt compound or other type of accelerator is dissolved or emulsified or chemically bonded to the polyester resin or epoxy resin, which acts as a film-forming agent in the finish to provide the desired amount of cobalt compound or other accelerator 35 gets incorporated into the fiber.

79 0 578 7 ............

ύ? 9 - 8 -

Fiber apret

Gamma-aminopropyltriethoxysilane 0.30

Water-soluble polyester resin 5.50

Lubricant (Cirrasol 185A) 0.30 5 Polyvinylpyrrolidone 1.50

Cobalt Octoate (10% Co) 4.00

Deionized water 88.40 100.00

10 i Example II

j Application of the accelerator system to finished products.

A. In preparing an emulsion-bonded glass fiber mat, a cobalt salt or other accelerator ^ 5 is added in an appropriate amount to the binder to provide the desired amount of cobalt salt or other accelerator in the glass fiber mat.

a) Mat binder

Polyvinyl acetate emulsion (50%) 7.50 20 Saturated polyester 3.00

Cobalt Sulphate (CoSO ^. 71 ^ 0) 0.40

Emulsifier (nonylphenol polyglycol ether) 0.02 Deionized water 89.08 20 100'00 b)

Polyvinyl acetate emulsion (50%), 7.50

Saturated polyester 3.00

Dimethylanlline 0.40 2g j Emulsifier (nonylphenol polyglycol ether) 0.02 | Deionized water 89.08 100.00 B. When preparing an emulsion bonded glass fiber mat, cobalt octoate or another cobalt compound or other accelerator is dissolved, emulsified, dispersed, or reacted in saturated polyester. ~ β (Γ5 7 8 7 -9 - - * · £.

which is used in the glass binder so that the desired amount of cobalt compound or other accelerator is incorporated into the glass fiber mat.

Mat Binder - 7 50 5 Polyvinyl Acetate Emulsion (50%) '

Saturated Polyester (Adipic Acid - Ethylene Glycol Type) 3.00

Cobalt Octoate (10% Co) 0.90

Emulsifier (nonylphenpl polyglycol ether) 0.02 10 Deionized water 88.58 100.00 C. When preparing a powder-bonded or emulsion-bonded glass fiber mat, a solution of a cobalt compound or a solution of another type of accelerator is sprayed onto the mat through a system of nozzles, placed above and / or below the mat conveyor, so that the desired amount of cobalt compound or other accelerator is incorporated into the glass fiber mat.

20 Spray liquid

Cobalt Sulphate (CoSO ^. 71 ^ 0) 2.00

Water 98.00 100.00 25 D. When preparing a glass fiber roving, a solution of a cobalt compound or other accelerator is applied by means of a suitable applicator or in a bath with subsequent drying, so that the desired amount of cobalt compound or other accelerator is incorporated in the fiber optic principle. Solution ί Cobalt sulphate (CoSO ^. ΊΕ ^ Ο) 5

Water 95 35 100

One or more of the above application methods 79057T7 7k9-10 can be used in the preparation of all other fiber products.

Modifications of the above are of course possible without departing from the scope of the invention.

Conclusions i! i »! j \ 79Ö5 7T7 i

Claims (13)

1. A method for preparing thermosetting fiber-reinforced plastic, using unsaturated synthetic resin and / or monomers, a catalyst, an accelerator system, and reinforcing fibers, characterized in that a menu bag of unsaturated synthetic resin and catalyst is reinforced with fibers in which an accelerator is incorporated, or in which a mixture of unsaturated synthetic resin and accelerator is reinforced with fibers in which a catalyst is incorporated. 10 2. Process according to claim 1, characterized in that the unsaturated synthetic resin is a polyester, polyacrylate, vinyl resin, polyurethane, or another unsaturated polymerizable compound such as styrene monomers or mixtures thereof. 3. Process according to claim 1 or 2, characterized in that the catalyst is a peroxide or another type of catalyst or mixtures thereof. 20 Method according to claim 1 or 2, characterized in that the accelerator system is based on compounds of Co, Fe, Mn, V, Pb, amine, or another type of accelerator, alone or in combination. 25 5. A method according to claim 1, 2, 3 or 4, characterized in that the reinforcing fibers are glass fibers, carbon fibers, metal wires, polyamide fibers: or other suitable fibrous materials, either in the form of untreated fibers, or prepared as a mat, roving, woven roving, chopped fiber, or in any other prepared state. 6. Process according to claims 1-5, characterized in that an unsaturated synthetic resin, to which an accelerator system has been added, is reinforced with fibers in which there is a catalyst incorporated. Reinforcing materials in the form of fibers and / or fillers, to be used in the preparation of reinforced thermosetting plastic according to claims 1-6, characterized in that an accelerator system or a catalyst is incorporated in the fibers and / or fillers. 1 °; Reinforcement material according to claim 7, characterized in that the fibers are glass fibers, carbon fibers, metal wires, polyamide fibers or another suitable fibrous material, either in the form of untreated fibers, or prepared as a matt, pre-woven, pre-woven , chopped fiber, or other prepared form. Reinforcing material according to claim 7, characterized in that the accelerator system contains Co, Fe, Mn, V, Pb components, amine, or another type of accelerator, alone or in combination. Reinforcing material according to claim 7, characterized in that the catalyst is peroxide or another type of catalyst or mixtures thereof. 11. A process for preparing reinforcing material according to claims 7-10, characterized in that the accelerator system I or the catalyst is dissolved, emulsified; dispersed or chemically bonded with a sizing known per se before this sizing is applied to the fibers. -12. Process for preparing accelerating materials 7905787 35 '--13 - • v according to claims 7-10, characterized in that the accelerating system or the catalyst is dissolved, dispersed, emulsified or chemically bonded with a fiber mat binder before this binder is applied to the mat. 13. Process for preparing reinforcing materials according to claims 7-10, characterized in that the accelerator system or the catalyst is applied to the fiber products in the form of a solution, emulsion, dispersion, or in solid form. 7905787 ".....